Diatomaceous earth filter apparatus and method

ABSTRACT

The invention provides an apparatus and method for removing diatomaceous earth and contaminants from a filter and for filtering liquid using diatomaceous earth. Embodiments of the method can include a washdown process, a backwash process, and a filtering process. Some embodiments of the apparatus can include one or more filter cartridges with cartridge tubes to increase flow during the backwash process. Some embodiments of the apparatus can include a backwash sprayer to disturb contaminants during the backwash process. Some embodiments of the apparatus can include a removable lid to access the filter cartridges during the washdown process.

BACKGROUND

Diatomaceous earth (“DE”) filters are often used to filter the water ofswimming pools, spas, water features, etc. DE filters typically includea septum with relatively large pores that DE cannot pass through. Addinga solution of water and DE to the filter can form a cake of DE on thesurface of the septum. The addition of the DE to the septum can create asmaller porous structure to improve the filtering capability of theseptum. However, contaminants caught in the DE over time can reduce thefiltering capability of the septum. As a result, the DE must be removedfrom the septum and reapplied. Various techniques have been used toremove the DE from the septum. These conventional techniques generallydo not remove all the contaminants from the septum, allowing thecontaminants to build up and eventually affect the performance of thefilter.

SUMMARY

In one embodiment, the invention provides a method of removingdiatomaceous earth and contaminants from a filter. The method caninclude opening a drain in a bottom tank and removing a lid to exposeone or more filter cartridges. The method can also include washing downthe filter cartridges to remove the diatomaceous earth and thecontaminants from a septum of the filter cartridges. The method canfurther include washing the diatomaceous earth and the contaminants outof the bottom tank through the drain, replacing the lid, and closing thedrain.

Another embodiment of a method of removing diatomaceous earth andcontaminants from a filter can include setting a backwash valve to abackwash position to reverse liquid flow. The method can includedirecting liquid flow from an interior to an exterior of one or morefilter cartridges. The method can also include directing liquid flowfrom a filter interior through a cartridge tube having holes to theexterior through a septum in order to remove the diatomaceous earth andthe contaminants from the septum. The method can further includedirecting liquid flow through a backwash sprayer to create turbulence ina bottom tank and directing liquid flow from the exterior of the filtercartridge and from the bottom tank to a backwash pipe.

Some embodiments of the invention provide a method of filteringcontaminants form a liquid using diatomaceous earth. The method caninclude removing substantially all air form a filter tank, sprayingunfiltered liquid into the filter tank to substantially fill the filtertank with liquid, and continuing to spray unfiltered liquid into thefilter tank to create turbulence. The method can also include directingthe unfiltered liquid from an exterior of one or more filter cartridgesthrough a septum coated with a solution including diatomaceous earth toan interior of the filter cartridges in order to filter the liquid. Themethod can further include sealing the filtered liquid within theinterior of the filter cartridges from the unfiltered liquid anddirecting the filtered liquid through the filter cartridges to anoutlet.

Some embodiments of the invention provide a diatomaceous earth filterfor filtering contaminants from liquid. The filter can include one ormore filter cartridges each including a septum coated with a solutionincluding diatomaceous earth. The filter cartridges can also include acartridge tube with holes to increase liquid flow during a backwashprocess. The filter can also include a backwash sprayer to spray liquidduring the backwash process in order to disturb contaminants in a bottomportion of a filter tank.

Another embodiment of the invention provides a diatomaceous earth filterincluding a bottom tank with a drain. The filter also includes one ormore filter cartridges at least partially positioned in the bottom tank.The filter cartridges can include a septum coated with a solutionincluding diatomaceous earth. The filter can also include a removablelid positioned over the filter cartridges and a clamp that secures theremovable lid to the bottom tank.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut-away perspective view of a DE filter according to oneembodiment of the invention.

FIGS. 2A and 2B are exploded views of the DE filter of FIG. 1.

FIG. 3 is a schematic view of a clamp, a lid, a bottom tank, and ano-ring of the DE filter of FIG. 1.

FIG. 4 is a perspective view of a clamp of the DE filter of FIG. 1.

FIGS. 5A-5D are flow charts of processes for operating a DE filteraccording to embodiments of the invention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

FIGS. 1, 2A, and 2B illustrate a DE filter 100 according to oneembodiment of the invention. As shown in FIG. 1, the DE filter 100 caninclude an air relief valve 105, a pressure gauge 107, a lid 110, one ormore filter cartridges 135, a clamp 145, a bottom tank 170 including adrain 195, and a backwash valve 220. In one embodiment, the lid 110 andthe bottom tank 170 can be constructed of chemical-resistant,fiberglass-reinforced polypropylene to withstand pressures created inthe DE filter 100. In some embodiments, the DE filter 100 can withstandinternal pressures up to about 50 pounds per square inch.

As shown in FIG. 2A, the DE filter 100 can include a compression spring115, an adapter 120, a top cartridge manifold 125, and an air bleedertube 130. As shown in FIG. 2B, the DE filter 100 can include one or morecartridge tubes 137, a backwash sprayer 138, a bottom cartridge manifold140, and o-ring 150, a ring backup 155, a baffle assembly 160, and anoutlet pipe 165. As also shown in FIG. 2B, the clamp 145 can include abarrel nut 175, a large inside diameter washer 180, a clamp spring 185,and a small inside diameter washer 190. As further shown in FIG. 2B, thebottom tank 170 can include the drain 195, an inlet adapter 200, anoutlet adapter 205, a first o-ring 210, and a second o-ring 215.

As shown in FIG. 2B, the inlet adapter 200 can include threads that canmate with threads of the baffle assembly 160. The first o-ring 210 canhave a diameter substantially equal to a diameter of the threads of theinlet adapter 200. The first o-ring 210 can fit over the threads of theinlet adapter 200 and form a water-tight seal between the inlet adapter200 and the bottom tank 170 when the inlet adapter 200 is coupled to thebaffle assembly 160. The baffle assembly 160 can spray unfiltered waterinto the DE filter 100. As also shown in FIG. 2B, the outlet adapter 205can include threads that can mate with threads of the outlet pipe 165.The second o-ring 215 can have a diameter substantially equal to adiameter of the threads of the outlet adapter 205. The second o-ring 215can fit over the threads of the outlet adapter 205 and form awater-tight seal between the outlet adapter 205 and the bottom tank 170when the outlet adapter 205 is coupled to the outlet pipe 165.

In one embodiment, the inlet adapter 200, the outlet adapter 205, andthe drain 195 can each have an internal diameter of at least about twoinches to enable sufficient water flow. In general, the high flow designof the DE filter 100 (including the filter cartridges 135) reducesenergy costs associated with operating the pump (not shown).

As shown in FIG. 2B, the outlet pipe 165 can include an elbow 250 sothat an opening 255 of the outlet pipe 165 can be positioned in asubstantially vertical position. The opening 255 can include threads. Insome embodiments, the opening 255 can include one or more o-rings and/orcan be press-fit to be coupled to the bottom manifold 140.

As also shown in FIG. 2B, the bottom manifold 140 can include arms 257with filter receivers 260, an air bleeder receiver 265, and an outlet270. In some embodiments, the outlet 270 of the bottom manifold 140 caninclude threads that can be coupled to the opening 255 of the outletpipe 165.

As shown in FIGS. 2A and 2B, the filter cartridges 135 can each includea cartridge tube 137, a top end cap 300, a septum 320, and a bottom endcap 305. The top end caps 300 and the bottom end caps 305 of the filtercartridges 135 can be in fluid communication with an inner side of theseptum 320 and can provide a flow path for liquid passing through theseptum 320. In one embodiment, the top end caps 300 and/or the bottomend caps 305 can be constructed of urethane.

The cartridge tubes 137, as shown in FIG. 2B, can be positioned insideeach one of the filter cartridges 135 and can extend substantially tothe top end caps 300. The cartridge tubes 137 can have holes along theirlength and can be open at both ends. During backwashing of the DE filter100, the cartridge tubes 137 can deliver a relatively large quantity ofwater to the top of the filter cartridges 135. The large quantity ofwater delivered to the top of the cartridge filters 135 can promotebetter cleaning of the septum 320. The DE and the contaminants can beforced off the top of the septum 320 initially and gravity can cause thewater to clean succeedingly lower portions of the septum 320 until theseptum 320 is substantially entirely clean. In some embodiments, inexcess of about 80% of the DE and contaminants can be removed from theseptum 320 by using the cartridge tubes 137, versus about 20% of the DEand contaminants being removed without the cartridge tubes 137.

In one embodiment, the septum 320 can be constructed of polypropyleneand can have pores about 25 microns to about 50 microns in diameter. Thepolypropylene material can be relatively heavy, for example, about 8ounces per square foot. The polypropylene can also have a coefficient offriction low enough to enable removal of the DE and contaminants fromthe septum 320. Water can be applied with low pressure to the septum320. Because of the low coefficient of friction of the septum 320, thelow pressure water can quickly remove substantially the entire quantityof DE and contaminants present on septum 320. In addition, the septum320 can have a corrugated construction and can have a linear length muchgreater than a circumference of the filter cartridge 135 (e.g., tenlinear feet). The corrugated construction can result in a large amountof filtering area in a minimum amount of space.

The filter cartridge 135 can be manufactured in different sizes (e.g.,eighteen, twenty-four, and thirty inch heights). The filter cartridges135 can be manufactured with multiple filtering areas (e.g., fifteen,twenty, and twenty-five square feet). Using multiple filter cartridges135 in the DE filter 100 can increase the filtering area (e.g., tosixty, eighty, or one-hundred square inches when using four filtercartridges 135). In other embodiments, less than four filter cartridges135, such as a single filter cartridge 135, can be used for smallerapplications.

A larger filtering area can increase the flow rate of water through theDE filter 100. For example, a DE filter 100 with 60 square feet offiltering area can have a maximum flow rate of about 120 gallons perminute or a turn-over capacity of 86,400 gallons every twelve hours. Bycontrast, a DE filter 100 with 100 square feet of filtering capacity canhave a maximum flow rate of 160 gallons per minute and a turn-overcapacity of 115,200 gallons every twelve hours. In addition, a largerfiltering area can provide more filtering capacity to extend the timeperiod between filter cleanings.

As shown in FIG. 2A, the top manifold 140 can include a plurality ofarms 350 extending from a center support 355. The ends of the arms 350can include cartridge plugs 360. The cartridge plugs 360 can be receivedby the top end caps 300 of the filter cartridges 135 and can form awater tight seal to prevent water from entering or leaving the filtercartridge 135 via the top end caps 300.

The air bleeder tube 130 can be positioned on the air bleeder receiver265 of the bottom manifold 140. The air bleeder tube 130 can extendupward to substantially the top of the DE filter 100 and can besupported by the center support 355 of the top manifold 140. Duringoperation, water in the bottom manifold 140 passing by the bottomopening of the bleeder tube 130 can have a Venturi effect on the airbleeder tube 130. The Venturi effect can draw air from the top of the DEfilter 100 into the air bleeder tube 130 and force the air out theoutlet port 205. During normal operation, substantially no air should bepresent in the DE filter 100. If substantially no air is present in theDE filter 100, the Venturi effect can draw water from the upper portionof the DE filter 100.

As shown in FIG. 2A, the adapter 120 can fit over the center support 355of the top manifold 140 and the air bleeder tube 130. The spring 115 canfit over the adapter 120 to bias the adapter 120 and the top manifold140 downward when the lid 110 is in place. Biasing the top manifold 140downward can force the plugs 360 of the top manifold 125 into the topend caps 300 to seal the upper portions of the filter cartridges 135 andto prevent water from passing through the top end caps 300.

As also shown in FIG. 2A, in some embodiments, the manual air reliefvalve 105 can include threads that can mate with threads in an aperture380 of the lid 110. The manual relief valve 105 can be opened to allowair and/or water in a top portion of the DE filter 100 to escape. Duringstart-up of the DE filter 100, the manual relief valve 105 can be opened(e.g., by turning the valve 105 a quarter-turn counter-clockwise) andcan allow any air trapped in the DE filter 100 to escape. Once all theair in the DE filter 100 has escaped, water can begin to escape throughthe manual relief valve 105, which can generally indicate thatsubstantially all the air in the DE filter 100 has been removed. Themanual relief valve 105 can be closed (e.g., by turning the valve 105 aquarter-turn clockwise) enabling pressure to build up in the DE filter100. The pressure can force water to flow through the septum 320, downthrough the bottom manifold 140, and out the outlet pipe 165.

As shown in FIGS. 2B and 3, the o-ring 150 can be positioned between thelid 110 and the bottom tank 170 and secured by the clamp 145. The o-ring150 can be positioned in a lower groove 390 around an upper edge 395 ofthe bottom tank 170. A lower edge 392 of the lid 110 can also include anupper groove 397. The o-ring 150 can provide a seal between the uppergroove 397 of the lid 110 and the lower groove 390 of the bottom tank170. As also shown in FIG. 3, the clamp 145 can be positioned around aflange 400 of the bottom tank 170 and a flange 405 of the lid 110. Acenter segment 410 of the clamp 145 can be positioned over the flange400 of the bottom tank 170 and over the flange 405 of the lid 110.

FIG. 4 further illustrates the clamp 145, which can include a T-bolt 425and a trunnion 430, in one embodiment. A first end 420 of the T-bolt 425can mount to the clamp 145 in a hinged configuration and a threaded end422 can pass through the trunnion 430. The large inside diameter washer180, the spring 185, and the small inside diameter washer 190 can bepositioned on the T-bolt 425. The large inside diameter washer 180 canbe positioned over the T-bolt 425 between the barrel nut 175 and thespring 185. The barrel nut 175 can be tightened to move the large insidediameter washer 180 toward the spring 185. The spring 185 can bias thesmall inside diameter washer 190 toward the trunnion 430. As the barrelnut 175 is tightened onto the T-bolt 425, the bias of the spring 185 onthe trunnion 430 can force a first end 445 and a second end 450 of theclamp 145 toward one another to tighten the clamp 145 around the lid 110and bottom tank 170. Securing the clamp 145 around the DE filter 100 cancause the lid 110 to compress the o-ring 150 toward the bottom tank 170to create a water tight seal of sufficient strength to withstand thepressure applied to the DE filter 100.

FIGS. 5A-5D illustrate processes for operating the DE filter 100according to embodiments of the invention. The DE filter 100 operatesunder pressure, and in order for the DE filter 100 to operate correctly,substantially all air must be removed. When starting the DE filter 100,the air relief valve 105 can be opened (block 500 of FIG. 5A) by turningthe air relief valve 105 a quarter turn counter-clockwise. A drain of aswimming pool can also be closed (block 505) and can enable a skimmer ofthe swimming pool to provide water to the DE filter 100. The pump of theswimming pool, spa, water feature, etc. (not shown) can be started(block 510). The pump can draw water from a swimming pool skimmer andcan force unfiltered water into the inlet adapter 200 and the baffleassembly 160. The baffle assembly 160 can spray the unfiltered waterinto the DE filter 100. During normal operation, when the DE filter 100is substantially filled with water, the baffle assembly 160 can createturbulence to assist in dispersing the unfiltered water, and thus anycontaminants in the water, to facilitate filtering of the water.

As the DE filter 100 fills with water, air in an upper portion of the DEfilter 100 can be forced out the air relief valve 105. Eventually,substantially all of the air in the DE filter 100 can be expelled andwater can flow from the air relief valve 105. An operator can determine(at block 515) whether a steady stream of water is exiting the airrelief valve 105. If water is not exiting the air relief valve 105, theoperator can determine (block 520) whether a period of time that shouldbe sufficient to fill the DE filter 100 has elapsed (e.g., 30 seconds).If the time period has not elapsed, the operator can continue to monitorthe air relief valve (at block 515). If the time period has elapsed, theoperator can shut the pump down (block 525). If the operator observes(block 515) a steady stream of water exiting the air relief valve 105,the DE filter 100 is substantially filled with water and the operatorcan close the air relief valve 105 (block 527) (e.g., by turning the airrelief valve 105 a quarter turn clockwise).

DE can be added to the DE filter 100 (block 530). In one embodiment, theseptum 320 of the filter cartridges 135 can include pores havingopenings of about 25 microns to about 50 microns in size. In oneembodiment, for example to achieve a level of filtering for a swimmingpool, the operator can add DE to the septum 320 to reduce the size ofthe openings to about one micron to about five microns in order tofilter out dirt, algae, and some forms of bacteria. In other words, theDE filter according to one embodiment of the invention can filtersubstantially all contaminants is excess of about one micron to aboutfive microns from any liquid able to pass through a one micron to fivemicron opening. A sufficient quantity of DE can be added tosubstantially coat the surface of the septum 320 (e.g., one pound of DEfor every ten square feet of septum 320 area). The DE can be added towater to form a thin, milky mixture and can then be introduced into theDE filter 100. The mixture can be drawn into the DE filter 100 throughthe inlet aperture 200 and distributed by the baffle assembly 160 tocoat the septum 320 of the filter cartridges 135.

If this is the first time the DE filter 100 is being run (block 535),the operator can record (block 540) the pressure inside the DE filter100. If this is not the first time the DE filter 100 is being run (block535) (i.e., following a backwash), the operator can check (block 545)the pressure to ensure that the pressure in the DE filter 100 is withinan operating tolerance (e.g., within four to five pounds per square inchof the recorded pressure). If the pressure is not within the operatingtolerance, the operator can turn the pump off (block 525). If thepressure is within the operating tolerance, the DE filter 100 canoperate to filter the water in the swimming pool, spa, water feature,etc.

As shown in FIG. 5B, the operator can periodically check (block 550) thepressure in the DE filter 100. When the pressure in the DE filter 100rises above a threshold (e.g., ten to twelve pounds per square inchabove the recorded pressure), the DE filter 100 may require cleaning.The operator can shut off (block 555) the pump. The operator candetermine (block 560) whether to clean the DE filter 100 by a washingdown process or a backwashing process.

FIG. 5C illustrates a process for washing down the DE filter 100according to one embodiment of the invention. Before opening the DEfilter 100, the pressure inside the DE filter 100 must be relieved(block 565). The pressure in the DE filter 100 can be relieved byopening the air relief valve 105 (e.g., by turning the air relief valve105 a quarter turn counter-clockwise). Water in the DE filter 100 canalso be removed (block 570) by opening the drain 195. The clamp 145 andthe lid 110 can be removed (block 575). As shown in FIG. 4, the clamp145 can be removed by loosening the barrel nut 175. The barrel nut 175can be completely removed or just loosened to a point that the clamp 145can be removed from the DE filter 100. Once the clamp 145 is removed,the lid 110 can be removed.

With the lid 110 removed, the filter cartridges 135 are exposed. Anoperator can decide (block 580) whether to wash the filter cartridges135 in place or to remove the filter cartridges 135 for washing. Washingin place (block 585) can be accomplished by hosing the filter cartridges135 down to remove the DE caked on the septum 320, along with anycontaminants trapped in the DE. The removed DE and the contaminants canbe washed out the drain 195. Removing and washing (blocks 590 and 595)the filter cartridges 135 can be accomplished by removing the topmanifold 125, lifting the filter cartridges 135 out of the bottommanifold 140, and washing each filter cartridge 135 individually. Thefilter cartridges 135 can then be replaced (block 600) by placing thefilter cartridges 135 into the bottom manifold 140 and placing the topmanifold 125 on the filter cartridges 135.

The bottom tank 170 and the lid 110 can also be washed out (block 605).After the filter cartridges 135, the bottom tank 170, and/or the lid 110are sufficiently washed out, the lid 110 can be replaced onto the bottomtank 170, the clamp 145 can be reattached, and the drain 195 can beclosed (block 610). The DE filter 100 can then be restarted by followingthe process beginning at block 510 of FIG. 5A.

FIG. 5D illustrates a process for backwashing the DE filter 100according to one embodiment of the invention. The backwash valve 220 (asshown in FIG. 1) can be set (block 630) to a backwash position and thepump can be restarted (block 635). The backwash valve 220, in thebackwash position, can reverse the flow of water into the DE filter 100(i.e., the water can be pumped into the outlet adapter 205 and can flowout of the inlet adapter 200). The backwash valve 220 can also include abackwash pipe (not shown) that can divert water coming from the DEfilter 100 to a drain or sewer so that the contaminated water comingfrom the DE filter 100 does not flow into the swimming pool. Theoperator can let the backwash run for a period of time (e.g., tenminutes) (block 640) to allow the DE caked on the septum 320 and anycontaminates contained in the DE to be washed off of the septum 320 andto flow out of the DE filter 100 through the backwash pipe.

The backwash sprayer 138 can be positioned between the air bleeder tube130 and the air bleeder receiver 265 as shown in FIG. 2B. Duringbackwashing, the water flowing into the bottom manifold 140 can beforced into the backwash sprayer 138. The water can exit the backwashsprayer 138 through jets positioned at opposing ends of the backwashsprayer 138. The backwash sprayer 138 can include a check valve whichcan prevent water from flowing unfiltered through the jets and into thebottom manifold 140 during normal filtering. In some embodiments, thebackwash sprayer 138 can be stationary. In other embodiments, the forceof the water exiting the jets can cause the backwash sprayer 138 torotate. The water exiting the jets of the backwash sprayer 138 cancreate turbulence in the bottom tank 170. The turbulence in the bottomtank 170 can cause contaminants that have settled into the bottom tank170 to become suspended in the water. The suspended contaminants canthen be flushed out the backwash pipe. The turbulence caused by thebackwash sprayer 138 can remove significantly greater contaminants fromthe DE filter 100 during backwashing and can result in a longer timeperiod before another backwashing is required. As shown in FIG. 5D, theoperator can then stop the pump (block 645). The backwash valve 220 canbe reset (block 650) to a normal operating position. The operatorcontinues at block 510 by restarting the DE filter 100, as shown in FIG.5A.

The backwash sprayer 138 can have any structure capable of generatingturbulence in the bottom tank 170. Embodiments of backwash sprayers caninclude jets on a bottom side of the bottom manifold 140, a plurality ofpulsating jets, a plurality of stationary jets, a plurality of rotatingjets, a plurality of jets cycling forward and backward, one or morehoses having a free moving outlet positioned in the bottom tank 170, arotating or stationary circular head having a plurality of jets, and oneor more rotating arms having one or more jets.

In some embodiments, a backwash brush or scraper can be positioned inthe bottom tank and can have jets to rotate the backwash brush orscraper during a backwash.

In some embodiments, a backwash sprayer can be coupled to the outletpipe 165. In other embodiments, a backwash sprayer can be coupled to thebottom manifold 140. Some embodiments can include more than one backwashsprayer and/or can include a plurality of backwash sprayers coupled tothe outlet pipe 165, the bottom manifold 140, and/or the air bleedertube 130.

Various features and advantages of the invention are set forth in thefollowing claims.

1. A method for removing diatomaceous earth and contaminants from afilter, the method comprising: opening a drain in a bottom tank;removing a lid to expose at least one filter cartridge; washing down theat least one filter cartridge to remove the diatomaceous earth and thecontaminants from a septum of the at least one filter cartridge; washingthe diatomaceous earth and the contaminants out of the bottom tankthrough the drain; and replacing the lid and closing the drain.
 2. Themethod of claim 1 and further comprising relieving air pressure andremoving water before removing the lid.
 3. The method of claim 1 andfurther comprising removing a clamp to remove the lid.
 4. The method ofclaim 1 and further comprising leaving the at least one filter cartridgein place while washing down the at least one filter cartridge.
 5. Themethod of claim 1 and further comprising removing the at least onefilter cartridge from the bottom tank, washing down the at least onefilter cartridge outside the bottom tank, and replacing the at least onefilter cartridge.
 6. The method of claim 1 and further comprisingremoving the at least one filter cartridge by removing a top manifoldand detaching the at least one filter cartridge from a bottom manifoldin the bottom tank.
 7. The method of claim 1 and further comprisingadding a solution with new diatomaceous earth to substantially coat theat least one filter cartridge.
 8. A method for removing diatomaceousearth and contaminants from a filter, the method comprising: setting abackwash valve to a backwash position to reverse liquid flow; directingliquid flow from an interior to an exterior of at least one filtercartridge; directing liquid flow from the interior through a cartridgetube having a plurality of holes to the exterior through a septum inorder to remove the diatomaceous earth and the contaminants from theseptum; directing liquid flow through a backwash sprayer to createturbulence in a bottom tank; and directing liquid flow from the exteriorof the at least one filter cartridge and from the bottom tank to abackwash pipe.
 9. The method of claim 8 and further comprising directingliquid flow through a bottom manifold into the cartridge tube.
 10. Themethod of claim 8 and further comprising reversing liquid flow for abackwash time period before resetting the backwash valve.
 11. The methodof claim 8 and further comprising adding a solution with newdiatomaceous earth to substantially coat the at least one filtercartridge.
 12. A method of filtering contaminants from a liquid usingdiatomaceous earth, the method comprising: removing substantially allair from a filter tank; spraying unfiltered liquid into the filter tankto substantially fill the filter tank with liquid; continuing to sprayunfiltered liquid into the filter tank to create turbulence; directingthe unfiltered liquid from an exterior of at least one filter cartridgethrough a septum coated with a solution including diatomaceous earth toan interior of the at least one filter cartridge in order to filter theliquid; sealing the filtered liquid within the interior of the at leastone filter cartridge from the unfiltered liquid; and directing thefiltered liquid through the at least one filter cartridge to an outlet.13. The method of claim 12 and further comprising closing a drain afterat least one of a washdown process and a backwash process.
 14. Themethod of claim 13 and further comprising adding a solution with newdiatomaceous earth to substantially coat the at least one filtercartridge.
 15. The method of claim 14 and further comprising drawing thesolution with new diatomaceous earth into an inlet and spraying thesolution with new diatomaceous earth in order to coat the septum. 16.The method of claim 12 and further comprising checking a pressure of thefilter tank to determine whether to remove contaminated diatomaceousearth.
 17. A diatomaceous earth filter for filtering contaminants fromliquid, the filter comprising: at least one filter cartridge including aseptum coated with a solution including diatomaceous earth, the at leastone filter cartridge including a cartridge tube with a plurality ofholes to increase liquid flow during a backwash process; and a backwashsprayer to spray liquid during the backwash process in order to disturbcontaminants in a bottom portion of a filter tank.
 18. The filter ofclaim 17 wherein the backwash sprayer rotates while spraying liquidduring the backwash process.
 19. The filter of claim 17 wherein thebackwash sprayer creates turbulence to disturb contaminants that havesettled in the bottom of the filter tank.
 20. The filter of claim 19wherein the disturbed contaminants are suspended in the liquid andremoved from the filter tank through a backwash pipe.
 21. A diatomaceousearth filter for filtering contaminants from liquid, the filtercomprising: a bottom tank including a drain; at least one filtercartridge at least partially positioned in the bottom tank, the at leastone filter cartridge having a septum coated with a solution includingdiatomaceous earth; a removable lid positioned over the at least onefilter cartridge; and a clamp that secures the removable lid to thebottom tank.
 22. The filter of claim 21 and further comprising a topmanifold and a bottom manifold, the at least one filter cartridge beingpositioned between the top manifold and the bottom manifold, the topmanifold sealing filtered liquid from unfiltered liquid, the bottommanifold directing filtered liquid to an outlet.
 23. The filter of claim22 and further comprising a spring to bias the top manifold toward a topend cap of the at least one filter cartridge in order to create a sealbetween the top manifold and the top end cap of the at least one filtercartridge.
 24. The filter of claim 23 wherein the top end cap isconstructed of urethane.
 25. The filter of claim 21 where the at leastone filter cartridge includes four filter cartridges connected inparallel to increase filtering capacity.
 26. The filter of claim 25wherein the four filter cartridges provide a filtering area of up toabout 100 square inches.
 27. The filter of claim 25 wherein the fourfilter cartridges allow for at least one of a flow rate of up to about160 gallons per minute and a turn-over capacity of up to about 115,200gallons about every 12 hours.
 28. The filter of claim 21 wherein atleast one of the lid and the bottom tank are constructed offiberglass-reinforced polypropylene.
 29. The filter of claim 21 whereinthe septum is constructed of corrugated polypropylene.
 30. The filter ofclaim 29 wherein the corrugated polypropylene has a weight of abouteight ounces per square foot.
 31. The filter of claim 29 wherein thecorrugated polypropylene includes pores about 25 microns to about 50microns in diameter.
 32. The filter of claim 29 wherein the corrugatedpolypropylene has a coefficient of friction low enough to allow removalof the diatomaceous earth and the contaminants.
 33. The filter of claim29 wherein the corrugated polypropylene has a linear length of about tenfeet.
 34. The filter of claim 21 and further comprising an inlet adapterand an outlet adapter, and wherein a diameter of the inlet adapter, theoutlet adapter, and the drain is at least about two inches to enablesufficient water flow.
 35. The filter of claim 21 wherein a filter areaof the filter is about 60 square feet to about 100 square feet.
 36. Thefilter of claim 21 wherein the filter removes contaminants having a sizegreater than about one micron to about five microns from the liquid. 37.The filter of claim 21 and further comprising a baffle assembly thatsprays unfiltered liquid into the bottom tank and the lid during afiltering process.
 38. The filter of claim 21 and further comprising abackwash sprayer that sprays liquid in order to disturb contaminants inthe bottom tank during a backwash process.
 39. The filter of claim 21wherein the clamp can withstand internal pressures up to about 50 poundsper square inch.
 40. The filter of claim 21 wherein the clamp includes aT-bolt, a trunnion, and a barrel nut.
 41. The filter of claim 21 andfurther comprising an o-ring positioned in grooves between the lid andthe bottom tank, and wherein the clamp compresses the o-ring to create afluid tight seal between the lid and the bottom tank.